title: Tumor necrosis factor-α 238 G/A polymorphism and risk of hepatocellular carcinoma: evidence from a meta-analysis.
abstract: BACKGROUND
  Tumor necrosis factor-α (TNF-α) plays a very important role in the development and progression of cancer. Many epidemiological studies have evaluated associations between the TNF-α 238 G/A polymorphism and hepatocellular carcinoma (HCC) risk, but the published data are inconclusive. Therefore, we performed the present meta-analysis.
  
  
  METHODS
  Electronic searches of several databases were conducted for all publications on the association between TNF-α 238 G/A polymorphism and HCC through July 2012. Asummary odds ratio (OR) with its 95% confidence interval (CI) were calculated to evaluate the strength of this association.
  
  
  RESULTS
  Eleven case-control studies with a total of 1,572 HCC cases and 1,875 controls were finally included in this meta-analysis. Overall, the TNF-α 238 G/A polymorphism was significantly associated with increased risk of hepatocellular carcinoma in three genetic comparison models (For A versus G: OR 1.32, 95%CI 1.04-1.69, P = 0.02, I2 = 40%; for AG versus GG: OR 1.32, 95%CI 1.02-1.71, P = 0.03, I2 = 40%; for AA/AG versus GG: OR 1.33, 95%CI 1.03-1.72, P = 0.03, I2 = 41%) when all studies were pooled. Subgroup analysis by ethnicity further showed that there was a significant association between the TNF-α 238 G/A polymorphism and risk of HCC in Asians under three genetic comparison models (For A versus G: OR 1.30, 95%CI 1.00-1.68, P = 0.05, I2 = 45% for AA/AG versus GG: OR 1.31, 95%CI 1.00-1.71, P = 0.05, I2 = 46%).
  
  
  CONCLUSIONS
  This meta-analysis provided convincing evidence that the TNF-α 238 G/A polymorphism is associated with increased susceptibility to HCC. However, more well-designed studies with large sample size are needed to validate this association in Caucasians.
authors.affiliation: 35 Ward of Transplantation, The Third Xiangya hospital of Central South University, Changsha, China.
authors.forename: Ke
authors.initials: K
authors.lastname: Cheng
authors.forename: Yu-Jun
authors.initials: YJ
authors.lastname: Zhao
authors.forename: Lian
authors.initials: L
authors.lastname: Liu
authors.forename: Jing-Jing
authors.initials: JJ
authors.lastname: Wan
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000235:genetics*; D016022:Case-Control Studies; D020022:Genetic Predisposition to Disease; D006801:Humans; D008113:Liver Neoplasms / Q000235:genetics*; D011110:Polymorphism, Genetic / Q000235:genetics*; D011379:Prognosis; D012307:Risk Factors; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics*
chemical_list: D014409:Tumor Necrosis Factor-alpha